There are numerous industrial processes that produce gas streams containing at least one of CO2, H2S, and HCl. It is often desirable to remove the CO2, H2S, and/or HCl from the other components of the gas streams, such as H2 and N2. One technique used to selectively remove CO2, H2S, and/or HCl from streams is to absorb the CO2, H2S, and/or HCl in an amine solution. Another technique used is to adsorb the CO2, H2S, and/or HCl on a molecular sieve. The scientific and industrial community has also used membranes to separate components in a process stream. There remains a need in the art for additional compositions, membranes, methods of making membranes, and methods of separating gases.